


Haikyuu!! and BNHA Age Regression!!

by Lover_boy



Category: Haikyuu!!, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Age Regression/De-Aging, Diapers, M/M, Non-Sexual Age Play
Language: English
Status: Completed
Published: 2021-01-31
Updated: 2021-01-31
Packaged: 2021-03-18 13:15:51
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 622
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29118846
Author URL: https://archiveofourown.org/users/Lover_boy/pseuds/Lover_boy
Summary: The little boys and carers of Karasuno Volleyball Club and Class 1-A! The two fandoms will be separated, i just wanted to put them into the same work. I will be doing requests if they're done politely and i know what to write for you; feel free to request characters that aren't in the tagsOther teams can be requested as well but i've only watched up to the third season so please don't request any new teams, i don't wanna disappoint you :(
Relationships: Bakugou Katsuki/Kirishima Eijirou, Jirou Kyouka & Kaminari Denki, Kageyama Tobio & Sawamura Daichi, Tsukishima Kei/Yamaguchi Tadashi
Comments: 8
Kudos: 60





	Haikyuu!! and BNHA Age Regression!!

**Author's Note:**

> THIS CHAPTER IS FOR HAIKYUU AND IT'S PROBABLY VERY OOC

Chapter 1: Kageyama Tobio's Struggle

Kageyama was NOT having the best week. He failed two quizzes, hurt his finger, got into a fight with his sister, AND covered his team jacket in mud all in 5 days. On top of all that, he hadn't gotten to feel small since the week started.

* * *

Sometimes, Kageyama felt small. That was the only way to describe it. He didn't know why it happened, what it was called, or if it was just him that felt it, but he liked it. He liked curling up in his blanket with a cartoon and a cup of warm milk before he fell asleep at night. He liked playing outside and trying to remember what games he'd play as a little kid. He liked imagining playing with toys and using bottles and pacifiers.

The issue was when he started needing it during the day. When he'd wrap himself in his jacket and scoot just a bit closer to Tanaka because he smelled like his dad. When he'd start biting his thumb in the middle of class to resist sucking it. When he started suggesting kid's movies at team sleepovers under his breath.

Kageyama knew it was a matter of time until someone noticed, but it was much sooner than he expected. But hey, it was Daichi's job as captain to worry about his players and he did which is why he brought it to Asahi's, Suga's, and Kiyoko's attention.

And so, with the brainpower and electronics of four third years, they started researching what was happening to Kageyama. It took about 20 minutes to find an explanation, surprisingly. And so, they notified the second years of the situation and told them to keep an eye on Kageyama.

* * *

That happened about three days before Kageyama's week went to shit. He wasn't allowed to practice because of his injury and he was irritated. He HATES being benched, not even getting to touch a volleyball, no way to deal with Tsukishima constantly bugging him.

Without even realizing, he started to slip back into that small space which stressed him out. 'Nonono, no, not here, not in front of everyone,' he thought to himself as he curled up and buried his face in his knees. No matter how hard he tried, he kept slipping farther and farther.

He started quietly fussing, continuing to stress himself out more and more until he was full on crying. Sugawara took notice and nudged Daichi who had Ukai call for a break. Daichi slowly made his way over and knelt beside Kageyama, "Hey kid, can you look at me?"

The blue-eyed boy took a deep breath and slowly turned his head to look up at Daichi who cooed as he pulled Kageyama closer. Everyone else looked over, listening to Kageyama sniffle and fuss for a moment. Tanaka and Noya slowly walked over and sat on the other side of the first year, Asahi sat behind him and carefully pulled Kageyama into his lap while smiling gently.

Kageyama looked around at his little crowd and all their smiles, then promptly started sobbing, making Asahi coo and gently stroke the bridge of his nose while Daichi stroked his hair and shushed him before he gave Noya a look which immediately had him rushing to his bag.

The motion made the setter look up but Tanaka gently guided him to lay back against Asahi's chest. Noya soon returned and shoved something into his mouth. A small, chewy, rubbery something; Noya had given him a pacifier. He grinned around the plastic, making everyone else coo or smile in response.

Except for one pair. Yamaguchi felt a tug on his sleeve and looked over to see a pouting and whining Tsukishima Kei. 


End file.
